The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A036260 Numbers k > 1 such that k mod ord2(k) is even, where ord2(k) is the order of 2 mod k. 3
 2921, 3017, 3473, 3479, 5767, 5969, 6167, 6377, 6497, 6913, 7223, 7519, 7567, 7751, 9017, 9271, 10199, 10447, 11431, 11929, 12719, 13439, 13609, 14513, 16583, 17009, 17143, 18631, 18809, 19313, 20737, 21119, 22337, 22351, 22537 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS These are all composite since for prime p, ord2(p) | phi(p) = p-1, whence p mod ord2(p) = 1. LINKS Amiram Eldar, Table of n, a(n) for n = 1..10000 MATHEMATICA Select[Range[3, 23000, 2], EvenQ[Mod[#, MultiplicativeOrder[2, #]]] &] (* Amiram Eldar, Jul 30 2020 *) CROSSREFS Cf. A002326, A007733, A036259. Sequence in context: A031552 A205253 A251353 * A180651 A180331 A043444 Adjacent sequences: A036257 A036258 A036259 * A036261 A036262 A036263 KEYWORD nonn AUTHOR David W. Wilson EXTENSIONS Offset corrected by Amiram Eldar, Jul 30 2020 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified May 26 22:59 EDT 2024. Contains 372847 sequences. (Running on oeis4.)